A Prince George's County police officer has been charged after he allegedly shot and killed a suspect who was handcuffed and wearing a seat belt inside a squad car on Monday night in Maryland.

The officer is reportedly currently in custody.

Cpl. Michael Owen Jr. is charged with second-degree murder, involuntary and voluntary manslaughter, first-degree assault and use of a firearm in the commission of a crime of violence, Prince George's County Police Chief Hank Stawinski said.

"I am unable to come to our community and offer you a reasonable explanation for the events that occurred last night," Stawinski said per NBC Washington.

The officer was called to the scene after a traffic incident was reported. When officers arrived, witnesses told Owen and another officer that a man had struck their vehicles.

The suspect was 43-year-old William Howard Green, who was found sitting in his car nearby, police said. According to reports, the officer suspected that Green might have been under the influence and then removed him from his vehicle. He was promptly handcuffed and placed in the front passenger seat of Owen's cruiser while waiting for a drug recognition expert to arrive.

Owen then got in the driver's seat next to Green.

Police say that Green was shot seven times by Owen. 

Two witnesses said they heard a struggle coming from the cruiser and heard loud bangs, but Stawinski says that these witnesses have not been found.

"They dragged him out and left him on the ground," his fiancée said. "He's still in handcuffs with his hands behind his back. They didn't even have the decency to take the handcuffs off."

The officer did not have a body camera, police said.

Prince George's County State's Attorney Aisha Braveboy released a statement following the arrest:

"We will seek truth and will vigorously pursue justice in a way that is fair and responsible," Braveboy said in the statement. "Once we have received all information and completed our own investigation and analysis, I assure you that my office will be transparent and accountable to the public about our findings and how we will move forward."